A lunch time project to quench my thirst of understanding Digital Signal Processing in a way that I may develop a gut feeling for digital filters and signals.

The idea is to visualize 2nd order IIR filter designing process. I believe that its simple maths and gut feeling.

Here is brief control flow for user:
1. Graphically give location of poles and zeros on z plane (complete, code in trunk)
2. that will be converted to time domain and frequency domain (targeted by 'displayfreqresponse' series)
3. as user adds/edits location of real/conjugate poles/zeros the effective transfer function be applied to a media file which is being played as user is interacting (targeted by 'realtimefiltering' series)